and deputy white house chief of staff under george w. bush. hagin provided security to big events, summits, trips to war zones. hagin says the secret service, the lead security service for the inauguration, will make sure buildings are clear of potential snipers, manhole covers welded shut, s.w.a.t. teams over the city. plain clothes law enforcement lingering in the crowd. bomb-sniffing dogs, and teams trained on mass destruction. >> dive team, intelligence analysts will be working around the clock. our hostage negotiators. >> reporter: that fbi official spoke to us inside the multiagency communications center, real time monitoring of surveillance cameras posted on buildings and roads and share tips and incidenident reports. with checkpoints, monitoring stations and other precautions, this stage, the parade route along pennsylvania avenue, where the real unknown comes in. often along here where the president gets out of his car. that's when the president is most exposed and the crowds are massive. >> if he gets out of his car and walks, what's